Notes

Overview

The Note Object is the most basic element of MusiStrata. It is created to represent Notes as they are defined in Western Music Theory, with a name and an octave value. Operator overloads have been defined between Notes and most other components to create new Notes.

Creating and Using a Note object

Valid Note Names are letters A to G.
The only allowed alterations are Sharps. An altered note can be specified by appending ‘s’ to the note name.

"""
class Note(object):
    def __init__(self,  Name: str = "A", Octave: int = 5):
        self._Name = NoteNames(Name)   # NoteNames is a class more or less the same functions as an enum
        self._Octave = Octave
"""

# Allowed note names when creating a note object
>>> MusiStrata.Components.Notes.ALL_NOTES
ALL_NOTES = [
    "A", "As", "B", "C", "Cs", "D", "Ds", "E", "F", "Fs", "G", "Gs"
]

# Creating a Note. Default values are Name="A" and Octave=5
>> Note()
Note(A5)

# Can specify values
>> Note("B", 6)
Note(B6)

# Append s to Name to create a Note with a sharp
>> Note("Cs", 5)
Note(Cs5)

# The note name can be access by the .Name property.
>> Note("C", 5).Name
"C"
# Name is actually a public property returning _Name.name. 
# The _Name property is a pseudo enum and works similarly.
>> Note("C", 5).Name.name
"C"
>> Note("C", 5).Name.value
0

# Octave can be accessed through the Octave property. A setter ensures it cannot be negative
>> Note("C", 5).Octave
5

The intent of this library is to represent a song as a succession of Notes, ordered into Structural classes, to then generate a midi file, or interface with other libraries.
As such a Note object has methods to return its height, aka its “note” property for a midi note_on/note_off message, as well as its frequency.
Remark: the height computation is what allows all comparisons, and tonal distance computations.

>> Note("C", 5).Height
72

>> Note("C", 5).Frequency
523.2

# This means it is also possible to create a note from its height
>> Note.FromHeight(72)
Note(C5)

Operations on Notes

The add and sub operators of the Note Class have been overloaded to allow special operations. Other operations are possible and implemented through radd and rsub of other components.

Notes and integers

# Adding a Note and a int returns a new note, translated by a given number of semitones
>> n + 4
Note(E5)

# Substractions are also supported
>> (n + 4) - 4 
Note(C5)

# Changes in Octave are handled automatically
>> n - 1
Note(B4)

Notes and Notes

# base note for all our examples
>> n = Note("C", 5)
Note(C5)

# Notes have a Height, defined by its Name and Octave, so comparisons are supported
>> n > n
False
>> n >= n 
True

# Can perform a substraction between two notes. Will return an integer representing tonal distance in semitones
>> n - Note("F", 4)
7
>> Note("F", 4) - n
-7

# Use the method ComputeRootedTonalDistance to ensure positive value is returned if needed, but this is mostly for internals
>> n.GetRootedTonalDistance(Note("F", 4))
7
>> Note("F", 4).GetRootedTonalDistance(n)
7